Reclosable lid for a food or beverage container and having a vacuum or pressure release button

ABSTRACT

A sheet metal lid has a rim portion removably secured and sealed to a container and the lid includes a vent button having a top wall portion surrounded by a side wall portion and an outwardly projecting flange portion. The flange portion of the button has a short arcuate score or shear line extending substantially into the sheet metal, and additional score lines extend into the flange portion at lesser depths to protect a coating on the inner surface of the lid. A resilient sealant material may be bonded to the inner surface of the vent button, and the opposing sheet metal portions of the score line form a small gap for releasing a vacuum or pressure from the container in response to a controlled downward pressure on the top wall portion of the vent button.

RELATED APPLICATION

This application is a continuation-in-part of application Ser. No.15/605,050, filed May 25, 2017.

BACKGROUND OF THE INVENTION

This invention relates to a closure or lid for a food or beveragecontainer as disclosed, for example, in applicant's U.S. Pat. No.5,979,688, U.S. Pat. No. 6,206,220, and U.S. Pat. No. 9,701,447 thedisclosures of which are herein incorporated by reference. These patentsare directed to a thin sheet metal closure or cap or lid for a sealedfood or beverage container wherein the closure is removably sealed tothe container and reclosable on the container. Commonly, the containeris formed of glass but may also be formed plastic or thin sheet metal,and the vacuum or pressure within the sealed container is released tofacilitate or simplify the removal of the closure or lid from thecontainer with reduced torque. Other forms of containers with reusableclosures for containers and having a vacuum or pressure releasestructure before the closure is removed from the container are disclosedin U.S. Pat. No. 3,410,436 and U.S. Patent Publication No. US2014/0103044,

As used herein, the term container includes a glass or sheet metal orplastic container, and the term lid includes any form of removableclosure such as a twist-on, twist-off sheet metal cap or a press-on,press-off sheet metal cap or lid for a container. The lid has aperipheral chime or rim portion with a bonded sealant material to form areleasable sealed coupling between the lid and the container.

The lid inner surface may also have a thin plastic coating whichprotects the contents of the container from exposure to the sheet metalforming the lid. In such an enclosed container and lid assembly, it hasbeen found desirable to add an easily activated and dependable vacuum orpressure release button to the lid, including after the lid has beenformed on tooling which shapes the lid and which may have bonded sealantmaterial on the inner surface of the rim portion of the lid. It is alsosometimes desirable to minimize the thickness of the sheet metal whichforms the lid and to provide some form of visible tamper-proofindication when vacuum or pressure has been released from the container,for example, as disclosed in U.S. Pat. No. 3,152,911.

SUMMARY OF THE INVENTION

The present invention is directed to an improved sheet metal removablelid for a container having a vacuum or pressure enclosed food orbeverage product and which includes a vacuum or pressure release buttonoperable with a controlled and dependable pressure to facilitate easyremoval of the lid, and to the tooling and method for producing the lid.The method steps of forming the lid are especially adapted for addingthe vacuum or pressure release button to a lid which has been pre-formedfor removably attaching to a glass jar or sheet metal container. Inaccordance with one embodiment of the invention, a sheet metal lidhaving a peripheral rim portion with a bonded sealant material has acenter portion formed with tooling in successive stages of a progressivedie to form an upwardly projecting vent button within an annular cavity.The button has a top wall portion surrounded by a side wall portionwhich is surrounded by a flange portion. A main or first score or shearline is formed within the flange portion adjacent the bottom of the sidewall portion, and a small portion of the score line is formed to producea small vent gap in response to a limited pressure on the top wall ofthe button. The score line extends through at least eighty percent ofthe thickness of the sheet metal forming the flange portion and mayextend completely through the sheet metal. Additional score lines atlesser depths than the main score line may be formed in the flangeportion of the button to prevent distortion of the flange portion andthe inner plastic coating when forming the button.

An arcuate or annular rib or bead may project downwardly within theflange portion of the vent button and extends adjacent the main scoreline. The opposing flange portions that define the score or shear linemay be pressed axially together or flattened for closing the shear lineand controlling the pressure required on the top wall to separate theflange portions and define the small vent gap. A sealant material may bebonded to the inner surface of the vent button below the score line andmay have a lip portion which extends to a retention bead. When the topwall of the vacuum release button is pressed downwardly, the opposingflange portions of the button separate and the lip portion of thesealant material extending to the bead peels away from the inner surfaceof the flange portion of the button and air or gas flows through the gapto release the vacuum or pressure within the container. When the buttonis released, the sealant recontacts the inner surface of the flangeportion of the button due to spring hinge action produced by the sheetmetal portions at the opposite ends of the main score line and by thereinforcement provided by the retention rib or bead. These sheet metalportions also limit the small vent gap.

Other features and advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical section of a conventional sheet metal lid beforesealant material is bonded to the rim portion of the lid;

FIG. 2 is a vertical section of the lid shown in FIG. 1 and with acenter portion of the lid formed with a vacuum or pressure releasebutton in accordance with the invention;

FIG. 3 is a vertical section similar to FIG. 2 and with a sealantmaterial added to the outer rim portion of the lid and also added to therelease button in accordance with the invention;

FIG. 4 illustrates the lid of FIG. 3 secured to the top portion of aglass container having a food or beverage product;

FIG. 5 shows the lid of FIG. 4 after the vacuum or pressure releasebutton has been depressed;

FIG. 6 is a fragmentary plan view of a vacuum or pressure release buttonconstructed in accordance with the invention;

FIG. 7 is an enlarged fragmentary section of the button, taken generallyon the line 7-7 of FIG. 6;

FIG. 8 is a larger fragmentary section of the lid, taken generally onthe line 8-8 of FIG. 6;

FIG. 9 is an enlarged fragmentary section of the lid and tooling forlancing or completely shearing the button on the shear line shown inFIG. 7;

FIG. 10 is an enlarged fragmentary section of the lid shown in FIG. 5after the button has been depressed;

FIG. 11 is an enlarged fragmentary section of the button after beingsheared or lanced as shown in FIG. 9 and compressed back together;

FIG. 12 is an enlarged fragmentary section of the button being lanced orscored by opposing tooling components;

FIG. 13 is a fragmentary section similar to FIG. 12 and showing thescored lid being flattened or compressed between tooling components;

FIG. 14 is an enlarged fragmentary section showing a lid being doublesheared or scored by opposing tooling components;

FIG. 15 is an axial section of a lid similar to FIG. 2 and having amodified vacuum release button formed in accordance with the invention;

FIG. 16 is a fragmentary plan view similar to FIG. 6 and taken on theline 16-16 of FIG. 15;

FIG. 17 is an enlarged fragmentary section of the lid shown in FIG. 15and taken generally on the line 17-17 of FIG. 16;

FIG. 18 is a vertical section of a lid formed in accordance with anotherembodiment of the invention and with a center portion formed with avacuum or pressure release button in accordance with the invention;

FIG. 19 is a plan or top view of the center portion shown in FIG. 18;

FIG. 20 is an enlarged fragmentary section of the button taken on theline 20-20 of FIG. 19;

FIG. 21 is an enlarged fragmentary section of the button taken on theline 21-21 of FIG. 19;

FIG. 22 is an enlarged fragmentary section of the tooling for formingthe main score line a secondary score line shown at 22 in FIG. 20;

FIG. 23 is an enlarged fragmentary section of the tooling for forming anancillary or third score lines shown at 23 in FIG. 21;

FIG. 24 is an axial section of a lid similar to FIG. 18 and showing amodified embodiment of the invention;

FIG. 25 is a plan or top view of the modified embodiment, takengenerally on the line 25-25 of FIG. 24;

FIG. 26 is an enlarged fragmentary section taken on the line 26-26 ofFIG. 25;

FIG. 27 is an enlarged fragmentary section taken on the line 27-27 ofFIG. 25;

FIG. 28 is a fragmentary section of tooling similar to FIG. 22 andshowing the score lines identified at 28 in FIG. 26;

FIG. 29 is an enlarged fragmentary section of the tooling for producingthe score lines at 29 in FIG. 27;

FIG. 30 shows the lid of FIG. 18 attached to a container having avacuum;

FIG. 31 shows the lid of FIG. 30 after the vacuum is released;

FIG. 32 is an enlarged fragmentary section shown at 32 in FIG. 31 afterthe vacuum is released;

FIG. 33 shows the lid of FIG. 24 attached to a container having a vacuumwithin the container;

FIG. 34 shows the lid of FIG. 33 after the vacuum is released; and

FIG. 35 is an enlarged fragmentary section of the lid shown in FIG. 34after the vacuum has been released.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a conventional sheet metal removable lid 20 having avertical center line 21 and commonly formed from thin sheet steel havinga thickness of about 0.007 or 0.008 inch. The lid 20 includes a flatcircular top wall 23 surrounded by peripheral horizontal rim portion 24with inwardly projecting portions 26 for releasably engaging or couplingthe lid 20 to an upper portion 28 of a container 30 (FIG. 4) in aconventional manner with a twist on, twist off coupling or a press-onand press-off coupling to the container. The inner surface of the rimportion 24 includes an annular bonded resilient sealant material 34(FIG. 3) such as a food grade PVC or plastisol, which forms a tight sealwith the container 30, in a conventional manner. Either before or afterthe annular layer of sealant material 34 is added to the lid 20, the lidis formed by progressive die stages to produce a removable lid 35 (FIG.2) having a push button vacuum or pressure release vent button 40constructed in accordance with the invention.

Referring to FIGS. 3-8, the vent button 40 is preferably circular andmay be located in the center portion of the lid 35. The vent button 40includes a substantially flat top wall portion 44 surrounded by a sidewall portion 46 which extends to a surrounding flange wall portion 48.The flange wall portion 48 extends to an outer flange portion 52 (FIG.8) connected by an inclined annular wall portion 54 (FIGS. 7 & 8) to thetop wall 23 of the lid. A downwardly projecting annular rib or bead 56projects below the flange wall portion 48. As shown in FIG. 7, asemi-circular or arcuate portion of the bead 56 is spaced outwardly fromthe side wall portion 46 of the button 40, and as shown in FIGS. 6 and8, the bead 56 extends at the bottom of the side wall portion 46 of thevent button 40.

Referring to FIGS. 6 & 7, an arcuate shear line 60 extends into theflange portion 48 and is located radially inwardly from the downwardlyprojecting bead 56 and adjacent the side wall portion 46 of the ventbutton. As shown in FIG. 9, the shear line 60 may extend completelythrough the flange portion 48 of the button 40 and this is performed bylancing the flange portion between shear die tooling components 63 and65 to separate opposing flange portions 48′ and 48″. After the shearingor lancing operation of FIG. 9, the opposing flange portions 48′ and 48″are pressed or compressed back together as shown in FIG. 11 and intoalignment by tooling components 67 and 69 to form a tight friction fitbetween the opposing flange portions 48′ and 48″.

The optimum desired downward pressure on the vent button 40 to separatethe flange portions 48′ and 48″ at the shear line 60, may also beobtained by pressing a shearing or scoring tool 75 (FIG. 12) into theflange portion 48 of the vent button 40 and against a tooling componentor anvil 78 having a slightly crowned top surface 79. The shearing orscoring tool 75 is pressed into the flange portion 48 by at least 80% ofthe sheet metal thickness of flange portion 48 so that the remaining orresidual 60′ at the shear line 60 is approximately 0.0008 inch or lessand forms the opposing flange portions 48′ and 48″. As shown in FIG. 13,the opposing flange portions 48′ and 48″ are then flattened or pressedback together between opposing flat surfaces of tooling components ormembers 82 and 83.

Referring to FIG. 14, the residual 85 at the shear line 60 of about0.0008 inch may also be obtained by opposing shearing or scoring membersor tools 87 and 88 which simultaneously shear or score from both the topsurface and the bottom surface of the flange wall 48 to form theopposing flange portions 48′ and 48″ and produce the residual 85 at theshear line 60.

Referring to FIGS. 15-17, the downwardly projecting rib or bead 56 iscircular within the flange wall portion 48 of the vent button 40 and isconcentric with the arcuate shear line 60 (FIG. 16). As also shown inFIG. 6 and FIG. 16, a generally triangular and tapered depression 90 isformed within the top wall portion 44 and provides an indication ofwhere the top wall should be pressed above the shear line 60 to separatethe opposing flange portions 48′ and 48″ as shown in FIGS. 5 and 10. Asalso shown in FIGS. 5 and 10, a sealant material 95 such as PVC orplastisol, which may be the same as the resilient sealant material 34,is added to the inner surface of the vent button 40 when the lid isinverted, and the sealant material includes a flange or lip portion 97(FIG. 10) which projects radially past the arcuate shear line 60 andreleasably attaches to the retention bead 56 formed in the flange wallportion 48 of the vent button 40.

Thus, when the top wall portion 44 of the vent button 40 is presseddownwardly with a predetermined pressure, the flange portions 48′ and48″ separate (FIG. 10) and the flange or lip portion 97 of the sealantmaterial 95 peels away from the retention bead 56 to form a very narrowspace or gap 100 (FIG. 10). The gap permits air above the vent button 40to flow into the container 28 or pressurized gas within the container toflow out of the container and eliminate any vacuum or pressure withinthe container. Since the sealant material 95 is in a fluid conditionwhen it is added to the vent button 40, and is heated, the sealantmaterial flows under the shear line 60 and is retained by the bead 56under the flange wall portion 48 of the vent button.

FIG. 18 shows another lid 110 constructed in accordance with amodification of the invention and which is similar to the lid 35 shownin FIG. 3 and which is partially identified with the same referencenumbers for similar structure or components but with the addition of aprime mark. In this embodiment, a vacuum or pressure release button 120has a top wall portion 122, and a surrounding side wall portion 124projects downwardly to a surrounding annular flange portion 126connected to the top wall portion 23′ of the lid by an annular inclinedwall portion 128. Referring to FIGS. 19 and 20, the flange portion 126of the push button 120 has a main or first score line 130 and a secondscore line 132 which is spaced radially outwardly from the first scoreline 130 by a distance D (FIG. 22) of about 0.025 inch. Both of thescore lines 130 and 132 have a “V” shaped center portion and extend anangle A of about 70 degrees with the main score line 130 tapering intothe metal to the center of the “V”.

As shown in FIG. 22, the score lines 130 and 132 are formed by a die 135which is pressed into the flange portion 126 supported by an anvil 138having rounded surfaces 139 below the V-shaped scoring portions 142 and143 of the die 135. When the score lines 130 and 132 are pressed intothe flange portion 126 against the anvil 138, the residual metalthickness R1 formed by the main or first scoring die portion 142 isabout 0.001 inch at the center of the “V”, and the residual metalthickness R2 formed by the scoring die portion 143 is about 0.002 inch.As shown in FIG. 20, the main or first score line 130 is locatedadjacent the bottom of the side wall 124 of the button 120. The secondscore line 132 is located radially outwardly from the first score line130 by about 0.025 inch.

Referring to FIGS. 19 and 23, an array or series of ancillary or thirdscore lines 148 are arcuate and radially within the flange portion 126of the button 120 and are formed by the scoring dies 149 and an anvil150 having a flat surface 151 to form a metal residual R3 within theflange portion 126 of about 0.0035 inch. Also formed within the top wall122 of the button 120 is a triangular recess 155 to form an arrowindicating where the top wall 122 should be pressed in order to rupturethe main or first score line 130 in response to depressing the top wall122 of the button.

FIGS. 24-27 show a modified form of a button 120′ which is identifiedwith some of the same reference numbers as used to describe the pushbutton 120, but with the addition of a prime mark. The difference in thebutton 120′ is that the surrounding annular side wall 124′ slopesdownwardly from the top wall portion 122′ to the annular flange portion126′. In all other respects, the score lines 130′, 132′ and 140′ areformed at the same depth as described above for the corresponding scorelines in FIGS. 22 and 23. Referring to FIGS. 28 and 29, these show thescoring dies which are the same as disclosed in FIGS. 22 and 23 exceptfor forming the first score line 130′, the second score line 132′ andthe third score lines 148′ in the flange portion 126′ having the slopingside wall portion 124′.

FIG. 30 illustrates the removable lid 110 with the push button vacuumrelease button 120 attached to a container 28 and shown slightlyconcaved as a result of a vacuum within the container 28. With a vacuumin the container 28, the top wall portion 122 of the push button 120 isbelow the chime or rim 24 of the lid 110. When the top wall portion 122of the button 120 is pushed downwardly, the main or first score line 130is slightly ruptured, as shown in FIG. 32 to define a small slit or gap100′ to release the vacuum or air within the container. As shown in FIG.31, when the vacuum is released, the top wall portion 122 of the button120 is still below the chime 24 of the lid 110.

FIGS. 33-35 are similar to FIGS. 30-32 except that the lid 110′ has apush button 120′ with a sloping or inclined annular side wall 124′ asshown in FIGS. 24-27, with the vacuum release button 120′ having themain or first score line 130′, the secondary score line 132′ and theancillary or third score lines 148′. The primary purpose of the secondscore lines 132 and 132′ and the third score lines 148 and 148′ are tominimize any distortion or wrinkles within the flange portion 126 and126′ and thereby protect the thin plastic coating on the inside surfaceof lid 110 and 110′.

It apparent from the drawings and the above description that a removablecontainer lid provided with a vent button 40 or 120 or 120′ inaccordance with the invention, provides desirable features andadvantages. For example, the forming the vent button with the score orshear line 60 as shown in FIGS. 9 & 11 or the shear or score lines asshown in FIGS. 12-14 and FIGS. 19-21 and 25-27, provide for obtainingprecision and dependable control over the desired pressure on the buttonto produce a very small gap 100 or 100′ between the opposing flangeportions. Also, when the pressure on the top wall portion is released,the spring hinge effect in the sheet metal produced by the annularflange portion on the opposite ends of the score line causes theopposing flange portions to return to their original opposing positionor causes the lip portion 97 of the sealant material to recontact theflange portion 48′, thereby closing the gap 100 to prevent or restrictliquid within the container from flowing through the gap 100 from thecontainer in the event the container was accidentally tilted onto itsside. After the vent gap is open, a light outward or upward pressure onthe opposing flange portions defining the gap will also cause theannular flange portion to snap overcenter, thereby closing the gap.

While the reclosable lids and vacuum or pressure release buttons andtheir method of construction herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to the precise methods and forms of release buttondescribed, and that changes may be made therein without departing fromthe scope of the invention as defined in the appended claims.

What is claimed is:
 1. A sheet metal lid having a vertical axis andincluding a top wall and a peripheral rim portion adapted to be securedto a container receiving a product and having vacuum or pressure, thelid comprising a portion of the top wall defining a vent button having atop wall portion, a surrounding side wall portion with an outwardlyprojecting flange portion extending around the side wall portion, aportion of the vent button having an arcuate shear line extendingsubstantially into the thickness of the sheet metal forming the ventbutton, the portion of the vent button having the shear line beingcompressed at the shear line to provide for obtaining a predetermineddownward pressure required on the top wall portion of the vent button toseparate opposing portions of the sheet metal at the shear line, aresilient sealant material bonded to an inner surface of the vent buttonand having a portion overlapping the arcuate shear line, and the portionof the sealant material being effective to form a narrow gap along theshear line in response to depressing the top wall portion of the ventbutton for releasing vacuum or pressure from the container.
 2. A lid asdefined in claim 1 wherein the shear line extends completely through thesheet metal and forms opposing portions for defining the gap, and theopposing portions of the sheet metal being axially compressed to besubstantially flush with the sheet metal adjacent the shear line.
 3. Alid as defined in claim 1 wherein the top wall portion of the ventbutton includes a generally triangular and downwardly projecting recessportion for indicating where to depress the top wall portion to separatethe opposing portions and produce the gap.
 4. A lid as defined in claim1 wherein the top wall portion of the vent button is below the top wallof the lid before pressure is applied to the top wall portion of thevent button.
 5. A lid as defined in claim 1 and including a circularbead in the flange portion of the vent button.
 6. A sheet metal lidhaving a vertical axis and including a top wall and a peripheral rimportion with a bonded sealant material, and adapted to be releasablysecured to a container receiving a vacuum or pressure enclosed product,the lid comprising, a portion of the top wall defining a vent buttonhaving a top wall portion, a surrounding side wall portion with anoutwardly projecting flange portion extending around the side wallportion, the flange portion having an arcuate shear line projecting intothe flange portion adjacent the side wall portion of the button andextending substantially through the thickness of the sheet metal formingthe flange portion, an arcuate bead within the flange portion anddisposed laterally outwardly from the arcuate shear line, the flangeportion being axially compressed at the shear line to obtain apredetermined downward pressure required on the top wall portion of thevent button to separate opposing flange portions of the sheet metal atthe shear line, a resilient sealant material bonded to an inner surfaceof the vent button and having a portion projecting laterally outwardlyonto an inner surface of the lid and overlapping the shear line, and theprojecting flange portion of the sealant material being effective todefine a narrow gap along the shear line in response to depressing thetop wall portion of the vent button for releasing vacuum or pressurefrom the container.
 7. A lid as defined in claim 6 wherein the opposingflange portions of the sheet metal at the shear line cooperate to definethe gap, and the opposing flange portions of the sheet metal beingaxially compressed to be substantially flush with the sheet metalforming the flange portion at the shear line.
 8. A lid as defined inclaim 6 wherein the top wall portion of the vent button includes agenerally triangular and downwardly projecting recess portion forindicating where to depress the top wall portion to separate theopposing flange portions and produce the gap.
 9. A lid as defined inclaim 6 wherein the top wall portion of the vent button is below the topwall of the lid before pressure is applied to the top wall portion ofthe vent button.
 10. A lid as defined in claim 6 wherein the bead iscircular.
 11. A method of adding a vacuum or pressure release button toa sheet metal lid having a vertical axis and a peripheral rim portionadapted to be secured to the top end portion of a container for aproduct and having a vacuum or gas pressure, the method comprising thesteps of pressing a portion of the top wall of the lid downwardly toform an upwardly projecting vent button, forming the vent button with atop wall portion and a surrounding side wall portion extending to aflange portion projecting laterally outwardly from the side wallportion, forming a downwardly projecting bead within the flange portionadjacent the side wall portion of the vent button, shearing an arcuateportion of the flange portion between the side wall portion and theretention bead to form an arcuate shear line extending substantiallythrough the metal thickness of the flange portion, compressing a topsurface and a bottom surface of the flange portion along the shear linebetween opposing tooling members to select the downward force requiredon the top wall portion of the vent button to shear the sheet metal atthe shear line, and bonding a sealant material to an inner surface ofthe vent button below the shear line and effective to define a vacuum orpressure release gap in response to depressing the top wall of the ventbutton above the shear line for releasing vacuum or gas pressure fromthe container.
 12. A method as defined in claim 11 wherein the step ofshearing an arcuate portion of the flange portion comprises shearingcompletely through the sheet metal and separating opposing flangeportions, and axially compressing the flange portions back together intoopposing alignment.
 13. A method as defined in claim 11 wherein the stepof bonding the sealant material to the inner surface of the button isperformed when a sealant material is bonded to the rim portion of thelid.
 14. A method as defined in claim 11 and including the step offorming a generally triangular recess portion into the top wall portionof the vent button.
 15. A method of adding a vacuum release button to asheet metal lid having a vertical axis and a horizontal peripheral rimportion adapted to be releasably secured to the open end portion of acontainer for a vacuum or gas pressure product, the method comprisingthe steps of pressing a portion of the top wall of the lid downwardly toform an upwardly projecting vent button, forming the vent button with atop wall portion and a surrounding side wall portion extending to anannular flange portion projecting laterally outwardly from the side wallportion, forming a downwardly projecting bead within the flange portionadjacent the side wall portion of the vent button, shearing an arcuateportion of the flange portion between the side wall portion and the beadto form an arcuate shear line extending substantially into through theflange portion, compressing a top surface and a bottom surface of theflange portion along the shear line between opposing tooling members tocontrol the downward force required on the top wall portion of the ventbutton to shear the sheet metal at the shear line, and bonding a sealantmaterial to an inner surface of the vent button below the shear line andeffective to define a vacuum or pressure release gap in response todepressing the top wall of the vent button above the shear line forreleasing vacuum or gas pressure from the container.
 16. A method asdefined in claim 15 wherein the step of shearing an arcuate portion ofthe flange portion is effect to separate opposing flange portions, andaxially compressing the flange portions back together into opposingalignment.
 17. A method as defined in claim 15 wherein the step ofbonding the sealant material to the inner surface of the button isperformed when a sealant material is bonded to the rim portion of thelid.
 18. A method as defined in claim 15 and including the step offorming a generally triangular recess portion into the top wall portionof the vent button.
 19. A method as defined in claim 15 wherein the stepof shearing an arcuate portion of the flange portion comprises shearingthe sheet metal into the top and bottom sides of the flange portion. 20.An aluminum sheet metal lid having a vertical axis and including a topwall and a peripheral rim portion with a bonded sealant material, andadapted to be releasably secured to a container receiving a vacuum orpressure enclosed product, the lid comprising, a portion of the top walldefining a vent button having a top wall portion, a surrounding sidewall portion with an outwardly projecting flange portion extendingaround the side wall portion below the top wall of the lid, the flangeportion having a first arcuate score line projecting into the flangeportion adjacent the side wall portion of the button and extendingsubstantially into the thickness of the sheet metal forming the flangeportion, the first arcuate score line including a V-shape portionextending less than seventy degrees relative to the vertical axis, andthe first score line being effective to rupture without rupturing thesecond score line in response to a predetermined downward pressure onthe top wall portion of the vent button to define a small narrow gapalong the first score line for releasing vacuum or pressure from thecontainer.
 21. The lid of claim 20 and including a second arcuate scoreline within the flange portion and spaced radially outwardly from thefirst score line in substantially parallel relation, the second scoreline extending into the flange portion at a depth less than the depth ofthe first score line, and the second score line including a V-shapeportion extending arcuately less than seventy degrees relative to thevertical axis.
 22. The lid of claim 21 and including third score linesextending into the flange portion at a depth less than the depth of thesecond score line and effective to minimize distortion of the flangeportion of the button when the flange portion flexes downwardly beforethe first score line is ruptured.
 23. The lid of claim 22 wherein thethird score lines are arcuate and extend partially around the side wallportion of the vent button.
 24. The lid of claim 23 wherein the thirdscore lines are concentric and include radially extending third scorelines within the flange portion of the vent button.
 25. The lid of claim21 wherein the flange portion of the vent button includes a third scoreline extending into the flange portion at a depth less than the depth ofthe second score line.
 26. The lid of claim 20 wherein the side wallportion of the vent button is annular and slopes downwardly from aroundthe top wall portion of the vent button to the flange portion of thevent button.
 27. The lid of claim 21 wherein the radial spacing betweenthe first score line and the second score line in the flange portion ofthe vent button is about 0.025 inch.
 28. The lid of claim 20 wherein thetop wall portion of the vent button includes a generally triangular anddownwardly projecting recess portion for indicating where to depress thetop wall portion to rupture the first score line in the flange portionand produce the gap.
 29. A sheet metal lid having a vertical axis andincluding a top wall and a peripheral rim portion with a bonded sealantmaterial, and adapted to be releasably secured to a container receivinga vacuum or pressure enclosed product, the lid comprising, a portion ofthe top wall defining a vent button having a top wall portion, asurrounding annular side wall portion with an outwardly projectingflange portion extending around the side wall portion below the top wallof the lid, the flange portion having a first score line extending intothe flange portion adjacent the side wall portion of the button andprojecting substantially into the thickness of the sheet metal formingthe flange portion, a second score line within the flange portion andspaced radially outwardly from the first score line, the second scoreline extending into the flange portion at a depth less than the depth ofthe first score line, the first score line being effective to rupturewithout rupturing the second score line in response to a predetermineddownward pressure on the top wall portion of the vent button to define anarrow gap along the first score line for releasing vacuum or pressurefrom the container, and a third score line extending into the flangeportion at a depth less than the depth of the second score line andcooperating with the second score line to minimize distortion of theflange portion when the flange portion flexes downwardly before thefirst score line is ruptured.
 30. The lid of claim 29 wherein the thirdscore line is arcuate and extends partially around the side wall portionof the vent button.